Unity + C# - "Resolution of the dependency failed"

Question

My application have a 10 WCFService ( WCFService Application on platform .NET Framework 3.5) with same software and hardware but only 1 takes this exception:

When user is logged in invoke this method:

  public IService Select(SelectServiceRequest request)
        {
            IAxxxService anagServ = IoC.Container.Resolve<IAxxxService>(request.GetRegisteredService().ToString());
            return xxxServ;
        }

• with GetRegisteredService() implementation with ClientIdentifier = 0 for first execution

  public RegisteredServices GetRegisteredService()
      {
          RegisteredServices res = RegisteredServices.Estxxx;
          if (ClientIdentifier == 0)
          {
              res = RegisteredServices.Anaxxx;
          }
          else if (ClientIdentifier == 1)
          {
              res = RegisteredServices.Prixxx;
          }
          else if (ClientIdentifier == 2)
          {
              res = RegisteredServices.Estrxxx;
          }
  
  
          else if (ClientIdentifier == 3)
          {
              res = RegisteredServices.LixxAnagrxx;
          }
  
          return res;
      }
  

  • with IOC code implementation and Initilization:

    internal class IoC{
      private static IUnityContainer container = new UnityContainer();
      private static bool isInitialized = false;
    
    public static IUnityContainer Container
    {
        get
        {
            if (!isInitialized)
            {
                lock (container)
                {
                    if (!isInitialized)
    
    
                        container.RegisterType<IService, EstxxService>(RegisteredServices.Esxxxxx.ToString());
                        container.RegisterType<IService, StaxxxService>(RegisteredServices.Anaxxxx.ToString());
                        container.RegisterType<IService, PrixxxService>(RegisteredServices.Prixxxx.ToString()); 
                        container.RegisterType<IService, LixxxAxxxService>(RegisteredServices.LixxxAnagxx.ToString()); 
                                    isInitialized = true;
    
                    }
                }
            }
            return container;
        }
    
    }
    

    }

i have this exception on execution method "Resolve":

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> Microsoft.Practices.Unity.ResolutionFailedException: Resolution of the dependency failed, type = "ApCon.IService", name = "Anagxxx". Exception message is: The current build operation (build key Build Key[ApCon.StandardService, Anaxxxx]) failed: The current build operation (build key Build Key[ApCon.StandardService, Anaxxxx]) failed:Index was outside the bounds of the array. (Strategy type DynamicMethodConstructorStrategy, index 0) (Strategy type BuildPlanStrategy, index 3) ---> Microsoft.Practices.ObjectBuilder2.BuildFailedException: The current build operation (build key Build Key[ApCon.StandardService, Anagrafe]) failed: The current build operation (build key Build Key[ApCon.StandardService, Anagrafe]) failed: Index was outside the bounds of the array. (Strategy type DynamicMethodConstructorStrategy, index 0) (Strategy type BuildPlanStrategy, index 3) ---> Microsoft.Practices.ObjectBuilder2.BuildFailedException: The current build operation (build key Build Key[ApCon.StandardService, Anagxxx]) failed: Index was outside the bounds of the array. (Strategy type DynamicMethodConstructorStrategy, index 0) ---> System.IndexOutOfRangeException: Index was outside the bounds of the array. at System.Collections.Generic.List1.Add(T item) at Microsoft.Practices.ObjectBuilder2.DependencyResolverTrackerPolicy.AddResolverKey(Object key) at Microsoft.Practices.ObjectBuilder2.ConstructorSelectorPolicyBase`1.CreateSelectedConstructor(IBuilderContext context, ConstructorInfo ctor) at Microsoft.Practices.ObjectBuilder2.ConstructorSelectorPolicyBase1.SelectConstructor(IBuilderContext context) at Microsoft.Practices.ObjectBuilder2.DynamicMethodConstructorStrategy.PreBuildUp(IBuilderContext context) at Microsoft.Practices.ObjectBuilder2.StrategyChain.ExecuteBuildUp(IBuilderContext context) --- End of inner exception stack trace --- at

Could it be the lock instruction? It seems that types weren't registered and isInitialized becomed true

Answer 1

Near as I can tell, you're registering named instances of IAnagrafeService, but trying to resolve a named instance of IService.

My guess would be that the first derives from the second, so something like this should work:

string name = request.GetRegisteredService().ToString();
IService anagServ = IoC.Container.Resolve<IAnagrafeService>(name);

(Or you could change the Unity registration, of course.)